An 01005 size component is 0.4 by 0.2mm, would that do?
This is the route I'd go. Saying "We can place 01005s successfully!" is more commercially valuable than saying "We can place 0.3mm pitch BGAs!" as there's a lot more demand for 01005s. I've looked through my part history, and the smallest I've placed lately are 0.35mm pitch devices, which are reasonably common. (ESD filters, single-gate logic, and others favor that pitch. Basically anything with a significant sales potential into cell phones.) TI don't even make any 0.3mm pitch packages as far as I can tell -- they have two drawings on the books (YHC and YHD) but no active products with them; YHD doesn't even have a publicly available drawing. 0.35mm, in contrast, has loads of parts available.